Manufacture of charcoal



(No Model.) 2 SheetsSheet 1.

H. M; PIERCE.

MANUFACTURE OF CHARCOAL. No. 278,731. Patented June 5,1883.

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{No Model.) 2 Sheet-Sheet 2. H. M. PIERCE.

MANUFACTURE OF CHARCOAL. No. 278,731. r Patented June 5,1883.

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r /J I I I 7 V V E PETERS. Pholo-Ulhugupher. Washingtmi. D. C.

UNITED STATES:-

PATENT FFIcE.

HENRY M. PIERCE, OF GRAND RAPIDS, MICHIGAN.

MANUFACTURE OF CHARCOAL.

SPECIFICATION forming part of Letters Patent No. 278,731, dated June 5, 1883.

Application filed December 21,1880. (No model.)

To all whmn it may concern:

Be it known that I, HENRY M. PIERCE, a citizen of the United States, residing at Grand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in the Manufacture of Charcoal, &c.; and I do hereby declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled. in the art to which it appertains to make and use the same, reference being had to the accom panying drawings, and to letters orfigures of reference marked thereon, which form a part of this specification.

In the drawings, Figure 1 is a perspective view of devices adapted to the carrying out of my invention. 2 is a sectional view of a kiln.

Like letters refer to like parts wherever they occur. e

My invention relates especially to the manufacture of charcoal, but is also adapted to the manufacture of coke, 850., and has for its object to rapidly and effectively cool the contents of the kiln or carbonizing-chamber after the carbonization or like process has been completed, whereby loss of time is avoided and the working capacity of the kiln proportionately increased, and also to avoid the shrinkage or loss in bulk which now occurs (in the manufacture of charcoal) from slow combustion taking place after the kiln has been closed.

To this end it consists in causing a circulation of gases which will not combine with carbon-such, for instance, as carbonic acid, carbonic oxide, nitrogen, &c.through the kiln or carbonizingchamber, said gases being main tained at alowe'r temperature than the contents of the carbonizing-chamber or kiln, and their circulation continued for such length of time after the extinguishing of the fire as shall be necessary to reduce the temperature to a point where the kiln can be opened and its contents removed, as will hereinafter more fully appear.

The following description will relate princi- Iatented in Canada February 28, 1882, No. 14,304.

I IVhile the invention is generally applicable in the manufacture of charcoal, it is especially so where the carbonization is done in kilns; and in order that the invention may be fully understood I will briefly describe the kiln and method commonly followed.

The kilns generally employed in the United States for carbonizing wood are adapted to contain from forty (40) to one hundred (100) cords of wood, are built of brick, either round and more or less tapering, oblong, or rectangular, as the'case may be, and are provided with chargingdoors, a series of air-inlets about four inches square and three feet apart, arranged in a tier near the bottom of the kiln, a series of gas-exits, and with firing-doors at the top of the kiln. The kiln is charged with the wood to be carbonized, the charging-doors closed, the wood fired through the firing-doors at or near the top of the kiln, and the firing doors properly closed. slow or limited combustion which takes place .in the kiln is admitted through the air-inlets around thebottom of the kiln, and the gases, &c., permitted to escape through the gas-exits located above the air-inlets.

The time consumed in carbonizing a kiln of wood will be some or seven days. As soon as the-person in charge finds that the wood is properly carbonized he closes and lutes up the air-inlets, gas-outlets, and any and all openings which would admit air to the interior of the kiln, and, to as far as possible hermetically close the kiln, frequentlywhitewashes the same. In spite of all these precautions, however, sufficient air will often gain admission so as to prolong slight combustion, delay the cooling of the kiln, and perceptibly diminish the yield of charcoal. Under the most favorable circumfore the kiln and its contents have cooled suf fiently to admit of opening the kiln.

I will now proceed to describe my invention, whereby I am enabled to cool the kiln and its contents in from twenty-four to thirty-six hours, and avoid shrinkagevand loss 'of char- The air to support the stances some six or seven days must elapse bcpally to the manufacture of charcoal, as SfiUW C02tl, referring for that purpose to the drawing the most important application of the invention; but I do not intend to limit my invention thereto, wishing it clearly understood that the invention is equally applicable to'c'okingovens and the like.

ings, which show apparatus that may be emplovecb si d construction, but which, for the pur- "poof this description, I have shown as con- 5 5. indicate ki1ns, which may be of any de-' structed on a plan described in my Patent No. 18-1, 898, November 28, 187 6that is to say, with a gas or vapor flue, a, which extends around the base of the kiln, and is provided with valved ports a, and with the usual air-inlets, b, charging-doors c (I, and firing door or doors 6 e.

The top of the kiln, or each kiln of a series, connected with a main, F, by a pipe, f, provided with a valve, f, and the main F is connected with a cooler or refrigerator, G. This refrigerator G may be of any suitable construction, though in the present instance it is shown as a tubular cooler composed of a series of tubes and two heads, indicates an exitpipe for drawing off any liquids which may condense in the cooler.

H indicates a pipe leading from the cooler or refrigerator to a fan, I, or other suitable means of inducing a circulation, and thence proceeds amain, K, from which pipes 7. (provided with suitable valves) connect with the gas and vapor chamber a.

The operation of these devices 'will be as follows: The kiln Ahaving been ehargedwith wood and the process of carbonization conducted in the usual or any approved manner until completed, the air-inlets'and all external openings are closed and luted up the usual way. In doing this a considerable volume of carbonic acid, carbonic oxide, and other gases will necessarily be confined in the kiln. The valves of the pipes f and 7c are opened, the fan I started, and the gases are drawn from the kiln through main F into the refrigerator G, where they are cooled, and pass thence through main K and pipes k to the vapor or gas flue a, to again circulate through kiln A. In this manner a continuous circulation of gas at a low temperature is established and the contents of the kiln rapidly cooled.

The drawings show a series ofkilns connected wit-h mains common to all, so that the kilns may be charged, the wood carbonized, and the kilns cooled in succession, as such an arrangement is the most economical; but it is evident that the invention is equally applicable to a single kiln, and that of any known construction The foregoing description has been made explicit as to the gas and apparatus employed, because it embodies what I believe to be the best method of carrying out my invention, and because the gas generated in thekiln is the most readily available; but I do not expect or intend -to be limited to either the gas or apparatus specified, for the following reasons, viz: First, it is evident that any apparatus which will cause a circulation through the kiln may be employed; secondly, any gas that will not combine with carbon may be used, and maybe obtained in any of the well-known ways; and, thirdly, the gas need not necessarily be refrigerated, as it can be used at any temperature lower than the temperature of the kiln.

Of course, the lower the temperature f th gas the more rapidly the kiln will 'be ooled ofi and the more time will be saved.

An incidental effect of the use of carbonicacid or equivalent gas in cooling off the charcoal is the extinguishing of any fire which may linger in the kiln, and the prevention of loss by useless combustion of the charcoal but the simple introduction of carbonic-acid or other gas for thepurpose of extinguishing the fire I do not herein claim, first, because both carbonic acid and steam have been heretofore employed, or their employment suggested, for such purpose 5 secondly, because carbonicacid and similar gases have been commonly employed for extinguishing fires.

It is essential to the proper carrying out of my invention that the non-combining gas shall at all times be lower in temperature than the temperature of the kiln and its contents.

In a patent granted to me February 29, 1876, No. 174,292, is shown and described a kiln, a conduit leading therefrom to an absorber, condenser, or chamber for eliminating the acids from the vapor, gases, &c., given'off from the kiln, and a fan for causing the circulation'ol' the gas, &c., through theabsorber and its re turn to the kiln for consumption therein. In such case the absorber may reduce the temperature of the gases slightly, but not so as to effect the objects set forth in the present invention, and therefore it is not the equivalent of the cooler or refrigerator herein specified, for it will be at once apparent that if the fire in the kiln is extinguished, as herein provided for, a point would soon be reached where the temperature of the absorber and the kiln would become equal and the desired result (cooling of the kiln) would not be materially expedited by causing the circulation of the gas through such a chamber;

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. As an improvement'in the manufacture of charcoal or coke, the method herein described for cooling the contents of the kiln, the same consisting in maintaining a circulation through the kiln of a non-combining gas such as carbonic oxide or carbonic acidsaid gasbeing maintained at a lower temperature than the kiln, and its circulation continued after the fire has been extinguished and until the contents of the kiln have been reduced to a low temperature, substantially as and for the purpose specified.

2. The method of extinguishing the fire of a charcoal-kiln or like chamber and cooling the charge thereof, which consists in cooling the carbonic-acid gas generated from the burning or carbonizing mass contained in the kiln, and then forcing it into the kiln and into and among the charge, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

, HENRY M. PIERCE.

- \XYitnesses WY. BITTER, Jr., H. BlMoUL'ron. 

